What does this mean from OWC?

[MythicFrost]

Hi, I'm wondering what this means from OWC when buying RAM?
(The red text is what I don't understand)

Mac Pro Memory Information
8 Total Slots, 32GB Supported
Must Upgrade using Matched Pairs
DDR2 240 Pin Fully-Buffered DIMM
72 Bit (64 bit + 8 bit ECC)
Mac Pro Specific Heatsink on Module
Four or More FB-DIMMs installed provides for best performance
FB DIMM technology takes advantage of multiple channel access. Apple recommends the use of 4 or more modules to take advantage of this 256-Bit Wide memory architecture. Modules must be installed in pairs, each module is 64 Bits Wide + 8 Bits for Error Correction (ECC).

Kind Regards

 

[SilentPanda]

It basically means if you want to add just 1 GB of RAM, you need to add two 512 sticks. Always add RAM in pairs, always remove in pairs on the Mac Pro.

 

[IgnatiusTheKing]

It means that you can't add one 4GB module and one 2GB module. You have to add RAM in matched pairs, meaning if you want to add any amount of RAM, you have to add it in increments of two identical sticks.

For instance, if you want to add 4GB, you can add four (two sets of two) 1GB sticks or you can add two 2GB sticks, but you cannot add a single 4GB stick.

Make sense?

 

[MythicFrost]

Yeah, thanks very much =)

Kind Regards